1. Field of the Invention
The present invention relates to an optical disc player, and more particularly, to an apparatus for reproducing program data recorded on an optical disc at a multiple velocity, which is capable of preventing deterioration of a screen quality even though a user reproduces the program data at the multiple velocity which is faster than a normal reproduction velocity.
2. Description of the Prior Art
In general, optical discs can be divided into discs for exclusive use of reproduction, discs for use of an additional record, and discs for use of erasing and rewriting according to functions and uses thereof.
The reasons these kinds of optical disc players are widely used are that they can reproduce signals with far better quality of picture and/or sound and that it is possible for them to randomly access to program data to be reproduced. In addition to these reasons, there is other reason that noise arising from unstable reproduction and modulation does not occur.
Furthermore, unlike a video cassette recorder or a cassette recorder, these optical disc players can directly move an optical pick-up unit toward a target track position in order to reproduce the data which is recorded on the optical disc within a very short time.
FIG. 1 is a view for showing a screen arrangement type of a group of picture (hereinafter, referred to as GOP) conventionally recorded on an optical disc. As shown in FIG. 1, in the program data recorded on the optical disc, I pictures are arranged at regular intervals. The program data such as B pictures and P pictures are arranged between the two I pictures to make one GOP.
FIG. 2 is a block diagram for showing a circuit diagram of an prior apparatus for reproducing program data at multiple velocity.
Referring to FIG. 2, the reproducing apparatus has a key inputting section 10, a control section 20, a reproducing section 30, a spindle motor driving section 40, and a spindle motor 50.
When a user operates a key of key inputting section 10 to generate a reproduction signal, optical disc D is rotated at a constant linear velocity and the program data recorded on optical disc D is reproduced at a normal velocity. At this time, when a reproducing key signal from key inputting section 10 generated by the user's key operation indicates a multiple velocity, control section 20 detects a position of the I picture of the program data reproduced from optical disc D by reproducing section 30.
When the position of the I picture is detected, control section 20 controls reproducing section 30 to read out or skip I pictures following the detected I picture according to the reproducing key signal indicating the multiple velocity. That is, when the reproduction key signal indicating the multiple velocity is a reproduction key signal indicating twice velocity, as shown in FIG. 2, control section 20 controls reproducing section 30 to read out the I pictures by skipping one by two after detecting a first I picture. When the reproduction key signal indicating multiple velocity is a reproduction key signal indicating three times velocity, control section 30 detects only one out of three I pictures after detecting the first I picture.
Accordingly, the program data recorded on optical disc D is possible to be reproduced at the multiple velocity even though optical disc D being rotated by spindle motor driving section 40 and spindle motor 50 rotates at the constant linear velocity.
However, the reproducing apparatus described above causes a loss of the program data because of skipping other I pictures among the respective I pictures for reproducing the program data at multiple velocity. Consequently, a screen quality of the program data reproduced from reproducing section is deteriorated.